Alar Toomre

Alar Toomre is an Estonian born astronomer and mathematician who immigrated to the United States in 1949.cite web|url = http://www.macfound.org/site/c.lkLXJ8MQKrH/b.1142683/k.77C6/Fellows_List__November_1984.htm|title = MacArthur Fellows November 1984|author = The John D. and Catherine T. MacArthur Foundation|accessdate = 2007-05-18] cite news|url = http://www-tech.mit.edu/archives/VOL_104/TECH_V104_S0792_P001.pdf|title = Toomre Awarded MacArthur Grant|publisher = The Tech|date = November 16 1984|accessdate = 2007-05-18|author = David B. Oberman|page = 1] He is a professor of applied mathematics at the Massachusetts Institute of Technology. [cite web|url = http://www.hpcwire.com/hpc-bin/artread.pl?direction=Current&articlenumber=17668|title = SDSC SIMULATION SHOWS COLLISION WITH ANDROMEDA|publisher = HPC Wire|date = December 5 2000] Toomre's research is focused on the dynamics of galaxies.

Career

Toomre received an undergraduate degree in Aeronautical Engineering and Physics from MIT in 1957 [cite web|url = http://www-tech.mit.edu/archives/VOL_076/TECH_V076_S0031_P006.pdf|title = Dormcon Prexy Vote Thursday Joe Bowers '57 Only Candidate|publisher = The Tech|date = February 26 1956|page = 6|accessdate = 2007-05-18] and then studied at the University of Manchester on a Marshall Scholarship where he obtained a Ph.D. in Fluid Dynamics.cite news|url = http://www-tech.mit.edu/archives/VOL_077/TECH_V077_S0116_P006.pdf|title = Alar Toomre, Course XVI Senior, To Receive Marshall Scholarship|date = April 9 1957|page = 6|accessdate = 2007-05-18] [cite news|url = http://www-tech.mit.edu/archives/VOL_104/TECH_V104_S0817_P012.pdf|title = Toomre Receives MacArthur Award|publisher = The Tech|date = November 16 1984|page = 22|accessdate = 2007-05-18]

Toomre returned to MIT to teach after completing his Ph.D. and remained there for two years. After spending a year at Princeton University, he returned again to MIT as part of the faculty, where he stayed. Toomre was appointed an Associate Professor of Mathematics at MIT in 1965. [cite news|url = http://www-tech.mit.edu/archives/VOL_085/TECH_V085_S0127_P003.pdf|title = Fifty-eight faculty promoted|publisher = The Tech|page = 3|date = April 14 1965|accessdate = 2007-05-18]

cientific Accomplishments

In 1964 Toomre devised an instability criterion for differentially rotating disks now known as the Toomre Instability. [cite web|url = http://www.hpcwire.com/hpc/853956.html|title = Star Maker Machinery|author = Tim Palucka|publisher = HPC wire|accessdate = 2007-05-18] Alternatively, it may be expressed as Toomre's Stability Criterion which is usually measured with the parameter "Q". [cite book|author = James Binney and Scott Tremaine|title = Galactic Dynamics|page = 363|publisher = Princeton University Press|editor = Jeremiah Ostriker|origdate = 1987|year = 1994|location = Princeton, New Jersey|language = English|isbn = 0-691-08445-9]

Toomre collaborated with Peter Goldreich in 1969 on the subject of polar wander, developing the theory of polar wander. [cite journal|url = http://www.sciencemag.org/cgi/content/full/287/5452/406?ck=nck|title = Did the Dinosaurs Live on a Topsy-Turvy Earth?|author = Richard A. Kerr|journal = Science|date = January 21 2000|pages = 406–407|volume = 287|number = 5452|accessdate = 2007-05-18|doi = 10.1126/science.287.5452.406] Whether true polar wander has been observed on earth, or apparent polar wander is accountable for all the observations of paleomagnetism remains a controversial issue. [cite web|url = http://adsabs.harvard.edu/abs/2004AGUFM.U31B..08C|title = A Short Review of True Polar Wander|author = V. Courtillot|publisher = American Geophysical Union|date = Fall Meeting 2004|accessdate = 2007-05-18 abstract #U31B-08]

Toomre conducted the first computer simulations of galaxy mergers in the 1970s with his brother Jüri Toomre. [cite web|url = http://scicom.ucsc.edu/SciNotes/9701/full/features/galaxy/Toomre.html|title = Toomre and the first models|publisher = Science Notes University of Santa Cruz|date = Summer 1997|accessdate = 2007-05-18] [cite web|url = http://findarticles.com/p/articles/mi_m1200/is_n14_v135/ai_7535883|title = Mixing it up in space: astronomers debate the role mergers play in galaxy formation|author = Karen Hartley|publisher = Science News|date = April 8 1989|accessdate = 2007-05-18] Although the small number of particles in the simulations obscured many processes in galactic collisions, Toomre and Toomre were able to identify tidal tails in his simulations, similar to those seen in the Antennae galaxies and The Mice. [cite web|url = http://hubblesite.org/newscenter/archive/releases/1997/34/astrofile/|title = Hubble Reveals Stellar Fireworks Accompanying Galaxy Collisions|date = October 21 1997|publisher = Space Telescope Science Institute|accessdate = 2007-05-18] [cite web|url = http://www.spaceref.com/news/viewpr.html?pid=8197|title = The Mice at Play|publisher = National Radio Astronomy Observatory|date = May 1 2002] [cite web|url = http://findarticles.com/p/articles/mi_m1134/is_1_109/ai_59210822/pg_2|title = Cannibals of the Cosmos - much more has become known about galaxies, since Edwin Hubble confirmed their existence in 1925|publisher = Natural History|author = Michael Shara|date = February 2000|accessdate = 2007-05-18] The brothers attempted to reproduce specific galaxy mergers in their simulations, and it was their reproduction of the Antennae galaxies that gave them the greatest pleasure. [cite journal|url = http://articles.adsabs.harvard.edu//full/1972ApJ...178..623T/0000658.000.html|title = Galactic Tails and Bridges|author = Alar Toomre and Jüri Toomre|journal = The Astrophysical Journal|year = 1972|pages = 623–666|volume = 178|accessdate = 2007-05-18|doi = 10.1086/151823] In 1977 Toomre suggested that elliptical galaxies are the remnants of the major mergers of spiral galaxies. [cite web|url = http://burro.astr.cwru.edu/JavaLab/GalCrashWeb/ellipt.html|title = Merger Remnants and Elliptical Galaxies] [cite web|url = http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=39833|title = Peering Far Back in Time to Uncover the Secrets of Galaxy Evolution|publisher = European Space Agency|date = December 1 1992|accessdate = 2007-05-18] He further showed that based on the local galaxy merger rate, over a Hubble time the observed number of elliptical galaxies are produced if the universe begins with only spiral galaxies. [cite web|url = http://www.casca.ca/ecass/issues/1997-DS/West/west-bil.html|title = THE GALAXY-CLUSTER-SUPERCLUSTER CONNECTION|author = Michael J. West|publisher = Canadian Astronomical Society/Société Canadienne D'Astronomie Cassiopeia No. 95|date = December 1997] This idea remained controversial and widely debated for some time. [cite web|url = http://www2.ifa.hawaii.edu/newsletters/article.cfm?a=187&n=18|title = Merging Spiral Galaxies Create Ellipticals|author = Robert Joseph|publisher = Nã Kilo Hõkũ|number = 13|date = Fall 2004|accessdate = 2007-05-18] [cite web|url = http://arxiv.org/abs/astro-ph/9908269|title = Galaxy Collisions|author = Curtis Struck|date = 1999|publisher = Physics Reports|volume = 321|pages = 1-137|accessdate = 2007-05-18]

From this work, the Toomre brothers identified the process of collision evolution as the Toomre sequence. [cite web|url = http://cosmos.swin.edu.au/entries/toomresequence/toomresequence.html?e=1|title = Toomre Sequence|publisher = Cosmos: The Swinburne Astronomy Online Encyclopedia|accessdate = 2007-05-18] [cite journal|url = http://adsabs.harvard.edu/abs/2001ASPC..249..179L|title = HST Observations of the Nuclear Regions of the Toomre Sequence of Merging Galaxies|author = Laine, S.; van der Marel, R. P.; Böker, T.; Mihos, J. C.; Hibbard, J. E.; Zabludoff, A. I.|journal = The Central Kiloparsec of Starbursts and AGN: The La Palma Connection, ASP Conference Proceedings|volume = 249|isbn = 1-58381-089-7|date = 2000|pages = 179] The sequence begins with two well separated spiral galaxies and follows them through collisional disruption until they settle into a single elliptical galaxy. [cite journal|url = http://www.aanda.org/index.php?option=com_base_ora&url=articles/aa/full/2001/10/aa10295/aa10295.html&access=standard&Itemid=81|title = HI line observations of luminous infrared galaxy mergers|author = W. van Driel - Yu Gao - D. Monnier-Ragaigne|journal = Astronomy and Astrophysics|date = 2001|volume = 368|pages = 64–73|accessdate = 2007-05-18|doi = 10.1051/0004-6361:20000509]

Awards and Honors

In 1993, Toomre received the Dirk Brouwer Award which recognizes "outstanding contributions to the field of Dynamical Astronomy". [cite web|url = http://dda.harvard.edu/newsletters/ddanews75.html|title = AAS Division on Dynamical Astronomy Newsletter 75|date = October 1993|accessdate = 2007-05-18|publisher = American Astronomical Society Division on Dynamical Astronomy] [cite web|url = http://dda.harvard.edu/brouwer_award/index.html|title = The DDA/AAS Brouwer Award|publisher = American Astronomical Society/Division on Dynamical Astronomy|accessdate = 2007-05-18]

Toomre was one of the 1984 recipients of the MacArthur Fellowship, popularly known as the "Genius Grant". [cite web|url = http://web.mit.edu/newsoffice/2004/macarthurs.html|title = MacArthur 'genius' grants go to four from MIT|author = Elizabeth A. Thomson|date = September 28 2004|publisher = MIT news office|accessdate = 2007-05-18]

References